Explosion-engine.



No. 636,298. Paten td Nov. 7,1899.

F. H. SMITH.

EXPLOSION ENGINE.

(Application filed July 81, 1899.)

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. 7 @MW QMLULW m m UNITED STATES ATENT union.

FREDERICK HUGH SMITH, OF DUMBLANE, SCOTLAND.

EXPLOSION-ENGINE.

SPECIFICATION forming part of Letters Patent No. 636,298, dated November'7, 1899. Application filed July 31,1899. Serial No. 725,567. (Nomodel.)

To all whom it may concern:

Be it known that LFREDERIOK HUGH SMITH, engineer, a subject of the Queenof Great Britain, residing at The Limes, Dumblane, Scotland, haveinvented certain new and useful Improvements in Explosion-Engines, ofwhich the following is a specification.

This invention relates to two-stroke cycleengines having a supplementarypiston to expel the products of combustion. I provide a spring tendingto force the supplementary piston toward the inner end of the cylinderand provide a non-return valve preferably in the supplementary piston.

Figure 1 is a longitudinal section of an engine constructed according tothis invention. Fig. 2 shows a modification.

a is the cylinder, and b is the main piston in it.

'c is the connecting-rod, pivoted to the piston b and the crank 01 onthe crank-shaft e.

f is a cam fixed to the crank-shaft e and operating the exhaust-valve gthrough the lever h, pivoted at j.

k is the admission pipe and port, supplying an explosive mixture of airand gas or vapor.

Z is a valve which is preferably provided on I the pipe 76.

m is the supplementary piston, having a non-return valve n in it, whichis normally held onto its seat by the spring 0.

p is a spring interposed between the pistons Z) and m and tending toseparate them, as shown in Fig. 1, or it may be placed outside thecylinder, as shown in Fig. 2.

q is the ignition apparatus of any ordinary construction.

The working of the engine is as follows: On the explosion taking placethe two pistons 12 and m are forced out together; but on opening theexhaust-valve g at the inner end of the cylinder the pressure isreduced, and the spring 19 causes the return of the supplementary pistonon before the other, so expelling the products of combustion. Meanwhilethe main piston 12 has uncovered the inlet-passage 70 in the outer endof the cylinder, and a charge is admitted into the space between thepistons. The return of the main piston b compresses this charge andforces it through the valve 12 in the supplementary piston m into thecombustion-chamber.

One great advantage gained by this engine is that it is more or lessself-governing, for after the exhaust is opened the spring 19 takes adefinite time to carry the piston m back to the inner end of thecylinder, and if the engine is running too fast for the piston m tocomplete its travel before the exhaust is closed then the products ofcombustion are not completely expelled and only a partial charge of theexplosive mixture is drawn in, and therefore the faster the engine isrunning the smaller and more diluted are the charges supplied to it.

The speed of the engine can be regulated either by adjusting thespring 1) or by turning the cock Z.

I claim- 1. The combination of a cylinder, a main piston, asupplementary piston, asprin g tending to force the supplementary pistonto the inner end of the cylinder, an inlet at the outer end of thecylinder, an exhaust-valve at the inner end of the cylinder, means foroperating it, a passage connecting the space between the pistons and theinner end of the cylinder, and a non-return valve in the passage.

2. The combination of a cylinder, a main piston, a supplementary piston,a spring tending to force the supplementary piston to the inner end ofthe cylinder, an inlet at the outer end of the cylinder, anexhaust-valve at the inner end of the cylinder, means for operating it,a passage through the supplementary piston, and a non-return valve inthe passage.

3. The combination of a cylinder, a main piston, a supplementary piston,a spring between the pistons, an inlet at the outer end of the cylinder,an exhaust-valve at the inner end of the cylinder, means for operatingit, a passage connecting the space between the pistons and the inner endof the cylinder, and a non-return valve in the passage.

4. The combination of a cylinder, a main piston, a supplementary piston,a spring between the pistons, an inlet at, the outer end of the.cylinder, an exhaust-valvetat the inner end of the cylinder, means foroperating it, a passage through the supplementary piston, and anon-return valve in the passage.

5. The combination of a cylinder, a main piston, a supplementary piston,a spring tending to force the supplementary piston to the inner end ofthe cylinder, an inlet at the outer end of the cylinder, a cock on theinlet, an exhaust-valve at the inner end of the cylinder, means foroperating it, a passage connecting the space between the pistons and theinner end of the cylinder, and a non-return valve in the passage.

6. The combination of a cylinder, a main the cylinder, a cock on theinlet, an exhaustvalve at the inner end of the cylinder, means foroperating it, a passage connecting the space between the pistons and theinner end of the cylinder, and a non-return valve in the passage.

8. The combination of a cylinder, a main piston, a supplementary piston,a spring between the pistons, an inlet at the outer end of the cylinder,a cook on the inlet, an eX- haust-valve at the inner end of thecylinder, means for operating it, a passage through the supplementarypiston, and a non-return valve in the passage.

FREDERICK HUGH SMITH.

Witnesses:

WILFRED OARPINAEL, FRED O. HARRIS.

